Bio theory Flashcards
Papers 1-11 + m/j 2024 + chap
1
Q
Difference between trace during exercise and rest
A
hmemrfo
2
Q
Outline how the body removes an oxygen debt.
A
Lactic acid is broken down by combining it with oxygen in the liver. The liver cells do this by aerobic respiration. Breathing rate and heart rate remains high= More oxygen faster.
how,how,ok
3
Q
Explain why some parts of a plant can act as both a source and a sink.
A
(acts as a ) source when it is (moving sucrose from) a region of production / photosynthesising ;
(acts as a ) sink when it is, growing / storing / a region of utilisation ;
4
Q
The rate of oxygen production was assumed to be the same as the rate of photosynthesis.
Suggest why the rate of oxygen production was not the same as the rate of photosynthesis.
A
Oxygen is used in respiration. The rate of photosynthesis may appear lower than it actually is.
5
Q
What does specificity mean?
A
(the enzyme) only able to act on a particular (specific) substance
6
Q
Explain how vaccination protects people against a transmissible disease such as measles.
A
1 harmless / dead pathogen is given ;
2 antigens are present on pathogens ;
3 (antigens) trigger an immune response ;
4 lymphocytes produce antibodies ;
5 ref. to specificity ;
6 memory cells are produced ;
7 antibodies destroy pathogen ;
8 providing active immunity
7
Q
Explain why the total biomass of the snakes is less than the total biomass of the mice.
A
1 snakes occupy a higher trophic level than mice ;
2 (most of the) energy is lost between the trophic levels ;
3,4 examples of energy loss (lost in exretion eg: urine), thermoregulation
5 not enough energy to sustain larger biomass at higher trophic levels
8
Q
Describe the function of chlorophyll.
A
Chlorophyll transfers light energy to chemical energy to make starch in photosynthesis.
9
Q
Describe the disadvantages of genetically modifying crops.
A
1 (additional) nutrient content may be (too) small ;
2 seeds may be expensive to purchase ;
3 farmers unable to save seeds ;
4 unknown health risks, to consumers ;
5 risk of cross-contamination with wild rice ;
6 reduction, in biodiversity / genetic diversity ;
7 consumers won’t buy GM products / ethical concerns ;
10
Q
Eggs contain protein.
Describe how the biological washing powder removes egg stains.
A
+chemical digestion
11
Q
Outline the roles of bile in the body. (Two points)
A
Bile emulsifies lipids (fats and oils) for faster breakdown by lipase by increasing the surface area of the lipids. Bile neutralises the stomach to provide optimum ph for enzymes.
12
Q
Describe the negative impacts to an ecosystem of large-scale monocultures.
A
-Loss of biodiversity
-Habitat destruction
-Soil infertility
-Soil erosion
-Increased pollution from run-off
-land could have been used for food prod
13
Q
Suggest why selective breeding should continue for many generations. Explain why scientists do this before selling them to farmers.
A
Reduce variation to maintain the desirable feature. They need to build up a large amount of seeds to sell to farmers. Ensures that the variety can grow in field conditions.
14
Q
Explain the role of hydrochloric acid in the alimentary canal.
A
Found in the stomach. Provides ph of 2 which kills harmful microorganisms in the food and provides the optimum for protease.
15
Q
Explain the risks to these species of birds that have decreasing populations.
A
The birds have an increased risk of ‘extinction, because of less genetic ‘variation, so they are less able to adapt to change in the ‘environment. (eve)
16
Q
Explain the advantages of the double circulation of the mammal.
A
- It allows high blood pressure in the body.
- It ensures an efficient oxygen supply to the body.
- It provides enough time for gas exchange.
- It prevents lung damage by keeping the pressure in the lungs lower.
aepp
17
Q
Describe the role of progesterone in pregnancy.
A
Maintains the thickness of uterus lining. Inhibists FSH and LH secretion. Prevents ovulation.
18
Q
Describe why conservation projects such as seed banks are important.
A
maintaining / increasing biodiversity ;
(moral) responsibility to save other species ;
protect / maintain ecosystems ;
by supporting recycling of nutrients ;
by supporting flow of energy in, food chains / food webs
reduce (plant) extinction ;
preventing loss of animal species that depend on plant species ;
possible genes, drug sources, crop plants / selective breeding ;
allows for future research ;
19
Q
Outline the process of artificial insemination.
A
Sperm is collected and inserted into the reproductive parts of female, eg: vagina at the time of their reproductive cycles when they are producing gametes. Female is ovulating during this time.
20
Q
Ways of conservation of a species
A
providing, habitats / protected areas ;
(laws to) prevent / limit, hunting / poaching ;
education ;
(captive) breeding programmes / use of AI ;
held prisoner
21
Q
Describe the expected appearance of a cell from a potato cube that has been immersed
in distilled water for 30 minutes.
A
Turgid, cell contents presses the cell wall.
22
Q
Outline how the carbohydrates made during photosynthesis are used in plants.
A
Glucose used to release energy,
converted to and stored as starch ;
converted to sucrose, sent to sink(s) ;
sucrose in nectar to attract pollinators ;
fructose / sucrose in fruits to attract animals ;
(glucose) converted to cellulose to build cell walls ;
lignin for cell walls ;
glucose used to make, amino acids / fatty acids ;
23
Q
Explain why body cells can have different specialised functions even though they contain the
same genes.
A
Not all genes are expressed. Cells only produce the specific proteins they need.
24
Q
Mutation causes formation of new alleles which increases genetic variation.
State two other sources of genetic variation in populations.
A
Meiosis
Random mating
Random fertilisation
25
Explain the structural adaptations of arteries.
arteries:
1 thick, muscular, wall to withstand the high blood pressure and is muscular to change it;
2 wall contains elastic tissue to stretch and recoil due to changing pressure ;
3 small lumen maintains high blood pressure ;
| wdm
26
Features of monocotyledons
{6 points}
one cotyledon ; parallel veins ; roots directly from the stem ; flower parts in multiples of three ; vascular bundles in stem arranged randomly ;
narrow leaves ;
27
Advantages of self-pollination
{4 points for both (self adv.), 2 disadv. for cross}
1 more chance of successful pollination ;
2 less pollen wasted ;
3 less need for pollinators (bees) and pollen
4 pollination can occur in plants that become isolated
(as occurs within same plant) ;
5 advantage to, farmers in maintaining (named) selected varieties / limiting variation (from one generation to the next) ;
Cross disadvantages: more energy required, two parent plants required (still need to find cross adv.)
## Footnote
4 pollens+energy+farmer+parent
28
Disadvantages of self-pollination
{5 points}
1 less variation
2 limited ability to, adapt more slowly to (named) change in environment ;
3 more chance of, genetic / inherited, disease ;
4 fewer individuals survive (new infectious) diseases ;
5 more competition between plants (as have similar adaptations) ;
## Footnote
variation, diseases
29
Explain why the area above the girdle in Fig. 4.1 will become swollen.
Use the terms source and sink in your answer.
1 glucose made in leaves, converted to sucrose and is translocated in the phloem
2 leaves act as a source and roots act as a sink ;
3 sucrose collects above the girdle ;
30
The DNA and Plasmid combo forms..
a recombinant
31
Apart from structural features, state five reasons why bacteria are useful for genetic modification.
reproduce rapidly ;
no ethical / welfare, issues ;
ability to make complex molecules ;
easy to maintain or store/ don’t take up too much space ;
share a genetic code with other (named) organisms ;
offspring are genetically identical
presence of plasmids
32
Which kingdom does bacteria belong to?
Prokaryotes.
33
[The different kingdoms]
What do I use to remember the 'often contain chloroplasts'?
Orange- often have chloroplasts
Umbrellas- usually
Make- may have cell wall/chloroplast
Stupid-some
Umbrellas + cell structure, multi or uni
Two of them belong to protocists
| Stupid is shared between protocits and prokaryotes
34
Give 3 points about the plant kingdom.
- feed by photosynthesis
- have cellulose cell walls and often have chloroplasts
- may have roots, stems and leaves
35
Give 3 points about the fungus kingdom.
- feed by digesting organic waste and absorbing it into their cells.
- usually multicellular
- have cell walls
36
Give 3 points about protoctist kingdom.
- some feed by photosynthesis or organic substances
- multi-cellular or uni-cellular
- may have cell wall or chloroplasts
37
Give 5 points about prokaryotes.
- some photosynthesis
- usually unicellular (unlike fungi which are usually multi, have cellwalls though)
- have a circular loop of DNA free in the cytoplasm
- often have plasmids
- no mitochondria
## Footnote
(the last ones)
38
Nitrogen gas is converted into a more reactive form.
Nitrogen fixation
39
# What would you call this process?
Amino acids from decomposing plants are released as ammonium ions.
Deamination
40
Outline the dangers of non-biodegradable plastic waste to marine animals.
does not break down ;
idea that ability to breathe affected ;
idea that ability to move affected ;
idea that ability to gain nutrition affected ;
injury/death ;
toxic / poisonous ;
blocks light producers, cannot photosynthesise ;
(so) less energy enters food webs ;
loss of (named), habitat / feeding / breeding area ;
more likely to be predated ;
idea that (plastic) accumulates up the food chain ;
41
Describe how the DNA and gene form a recombinant plasmid.
The same restriction enzyme...so that the sticky ends have complementary base pairs and can join together by using DNA ligase.
42
Explain the reason for constantly rotating plant A.
negating the effect of gravity, on one side of the plant (only) ;
(used as a control) to compare with (the response of) plant
B ;
43
Explain the plant hormone process.
Auxin is prod in the tip and diffuses down the shoot. It collects on one side of the plant and stimulates cell elongation. The plant grows, bending upwards.
44
Explain why the egg cell contains stores of protein and fat.
The stores provide energy for mitosis. Protein makes the cytoplasm and enzymes.
45
Describe how an embryo is formed from a zygote.
A zygote divides by mitosis. This is repeated again and again, forming a ball of stem cells which are genetically identical.
46
What does a diaphragm do?
Changes the volume of the thorax
47
What does the spinal cord do?
coordinates responses
connects CNS and PNS
48
What does a relay neuron do?
connects neurons, transmits impulses
49
What does the trachea contain?
contains cilia to move mucus out of the airway
50
Where would a receptor molecule for a neurotransmitter
be found on a motor neuron?
Tip of dendrite
51
Explain how the neuron is adapted for transmitting impulses.
Neurons have long axons to transmit impulses over long distances and many branches (dendrites) to connect with relay neurons. Mitochondria provide energy for neurotransmitter production. Vesicles carry and release neurotransmitters into the synapse, while receptor molecules receive signals from the next neuron.
52
Amylase:
organ where
enzyme is
secreted
organ where
the enzyme
acts
products of
digestion
salivary glads or duodenum (1)
mouth
maltose
53
Pepsin:
organ where
enzyme is
secreted
organ where
the enzyme
acts
products of
digestion
stomach
stomach
amino acids
54
lipase:
organ where
enzyme is
secreted
organ where
the enzyme
acts
products of
digestion
pancreas
small intestine
/ duodenum
/ ileum
fatty acids and
glycerol
55
Maltase:
organ where
enzyme is
secreted
organ where
the enzyme
acts
products of
digestion
small intestine (by cells lining the small intestine)
epithelial lining
of the small
intestine
glucose
56
Chemical fertilisers have helped farmers to increase food production.
Discuss the negative impact on the natural environment of using chemicals, other than
fertilisers, in modern farming methods.
1 pesticides / insecticides / herbicides:
2 kill, non-target species (in natural environment) ;
3 example of specific impact from harm of non-target
species ;- disturbs flow of energy
4 loss of biodiversity / disrupt food chains ;
5 ref to resistant organisms or super, bugs / weeds ;
6 pollute / destroy / AW, non-target / named, area / habitat ;
7 (antibiotics cause) antibiotic-resistance ;
57
State the process which can be used to develop crop plants that can produce proteins
from other species.
genetic modification
58
Explain how cells in plants keep them upright.
plants have cell walls ;
pressure of water pressing against cell wall / ref. to turgor ;
ref. to xylem (offering support) ;
MP4 e.g. ref. to lignin
59
State the type of microorganism that contains chlorophyll.
some protocists
60
Suggest why the researchers determined the concentration of chlorophyll rather than
counting the number of microorganisms in the sample.
organisms too small, so difficult to count
61
Using the information in Fig. 5.3, identify the day when the water was the most transparent.
biggest gap between depth and chlorophyll concentration
62
Explain why the transparency of the water is important for organisms that contain
chlorophyll.
to absorb / receive, (enough) light (energy) ;
(light) is necessary for photosynthesis ;
(for the organisms) to make sugars / starch / to convert light
(energy) into chemical energy ;
63
Explain the consequences of the death of these organisms to the lake ecosystem.
When organisms die, eutrophication occurs, leading to an increase in bacteria which are decomposers.
These bacteria respire aerobically, reducing dissolved oxygen in the lake, causing the death of fish.
Additionally, the death of producers results in less food for consumers.
64
List structural adaptations of insect-pollinated flowers.
2024 answer:
stigmas / style / carpel, within flower ;
anthers / stamens, within flower;
conspicuous, large, colourful petals form a landing platform ;
spotted pattern (to attract insects) ;
2022:
nectar ;
spiky pollen ;
sticky stigma ;
strongly scented
often have nectaries at the base of petals
large quantities of pollen
65
State morphological features that can be used to distinguish flowering plants from
ferns.
flowers, fruit, leaves, pollen, ovules
66
State what protein biotechnologists will use to increase the volume of juice produced from
pear fruit.
pectinase
67
State the function of mitochondria
site of aerobic respiration, release energy
68
State one feature of plants that is used to distinguish them from fungi.
cell wall in plants are cellullose
(fungi are made of chitin)
presence of chloroplasts
69
Yeast is a fungus that can respire to produce ethanol.
State the balanced chemical equation for this type of respiration in yeast.
C6H12O6 → 2C2H5OH + 2CO2
70
aerobic respiration chemical equation
C6H12O6 + 6 oxygen = 6 carbon dioxide + 6 water
71
photosynthesis chemical equation
aerobic respiration reversed
72
anaerobic for humans
glucose = lactic acid
73
(To do with the effect of sugar on respiration in yeast cells)
Suggest the reason for the oil layer in the apparatus shown in Fig. 1.1.
prevent oxygen from entering
allowing carbon dioxide to escape
74
State one reason why no more carbon dioxide gas was produced after 35 minutes by the yeast in a sugar solution, shown in Fig. 1.2
sugar has been used up
75
State one way in which humans use the carbon dioxide gas produced by yeast cells.
to make dough rise
76
State the name of one gas, other than carbon dioxide, that contributes to the enhanced
greenhouse effect.
methane
77
Describe how the events that occur at a synapse generate an impulse in the next neuron.
Neurotransmitter molecules released from vesicles into synaptic gap.
Neurotransmitters diffuse across gap and bind to receptor proteins on the next
neurone. This triggers an electric impulse in the next neurone.
78
accomodation
changing the shape of the lens to focus on an object at different distances from the eye (rpt) (csf) (folk and far NOT together) + light is focused onto the retina
79
Describe the distribution and function of rods and cones in the eye.
distribution:
1 both found in retina
2 high concentration of cones / no rods, are found in the fovea
3 nothing at blind spot
function:
4 both detect light (are receptor cells)
5 rods respond to dim light and give black
and white image ;
6 cones respond to bright light and detect colour
80
State the events in the life cycle diagram for organism 1 that would not be present
in a life cycle diagram for asexual reproduction.
formation of gametes, fertilisation
81
Limiting factors for rate of photosynthesis.
light intensity, CO2 concentration, temperature, stomata (number of chloroplasts, water)
82
What does the cervix do?
dilates in the process of birth
83
What does the oviduct do?
site of fertilisation
84
What does the uterus lining do?
site of implantation
85
Describe the function of the placenta in humans.
1 gas exchange: oxygen transfers to fetus from mother / carbon dioxide transfers to
mother transfers from fetus ;
2 transfers of (dissolved) nutrients, from maternal / to fetal
(circulation);
3 transfer of excretory products, from fetal / to maternal
(circulation) ;
4 (transfer of nutrients / excretory products) by diffusion ;
5 secretes progresterone
6 passive immunity provided (to fetus) ;
7 separates fetal and maternal blood supply ;
86
State two functions of the amniotic fluid that is found in the amniotic sac.
1 provides support to fetus ;
2 protect fetus from (mechanical) shock ;
3 maintains temperature (of fetus) ;
4 allows movement (of fetus)
5 prevents dehydration ;
6 ref. to swallowing of (amniotic) fluid / involved in digestive tract and lung development
7 provides sterile environment ;
87
Describe the pathway taken by the products of protein digestion from the villi to the liver.
Amino acids move into capillaries in villi then are carried in blood plasma and travel to the hepatic portal vein ;
88
Explain how the body provides a suitable pH for lipase activity.
Bile is an alkaline liquid produced in the liver and stored in the gall bladder. Bile neutralises the gastric juices, which results in a suitable pH for lipase activity.
89
The valves in the heart.
Between the atrium and ventricle: (atrioventricular valves) bicuspid and tricuspid (right)
semi-lunar: ones at the top, prevent backflow
90
Arota transports blood from the ... to the ...
left ventricle; rest of the body
91
State two uses of water in a plant.
- water is needed for photosynthesis
- act as a solvent for transportation in plant
- germination
- for support
- medium for metabolic reactions (chemical)
92
when:
ovulation (egg is released) is most likely to occur ................................................................
shedding of the uterine lining occurs. ..............................................................
LH is high, usually 12,13,14,15, or 16
when hormones are on the low, 1-8
93
Describe the role of FSH in the menstrual cycle.
stimulates ovaries to release of oestrogen ;
stimulates eggs to, mature / develop (in the ovary) ;
94
State a conclusion for the results shown in Table 5.1 and Table 5.2. (Plants in North America compared to Europe)
greater leaf area
95
Explain how the monkey flower plants have developed a larger leaf area over time.
Mutation causes variation in a species. The plants were in competition for resources such as light. Plants with larger leaf area are better adapted, because larger leaves absorb more sunlight.
Plants with larger leaves survived and reproduced, passing on the large leaf alleles to its offspring. This occurs over many generations until larger leaves are common in population. This process is called natural selection.
96
State the names of two processes that add carbon dioxide to the atmosphere.
respiration ;
combustion ;
decomposition
97
Describe the effect on the environment of additional carbon dioxide in the atmosphere.
CO2 is a greenhouse gas which contributes to global warming. The sea level rises.. Weather events are more often and stronger eg: ... With more CO2, the effects of global warming will worsen even further.
98
State two advantages of using a pyramid of energy rather than a pyramid of biomass to
represent a food chain.
more accurate:
shows actual energy transfer ;
time is taken into account ;
99
Explain one way that fishing can be managed to conserve fish stocks.
closed seasons ;
protected areas ;
quotas ;
education ;
smaller nets ;
larger mesh size ;
monitoring ;
= prevents overfishing and allows fish to breed
100
What does the muscle tissue in the stomach do?
makes the wall of the stomach move in and out, churning the food and mixing it up with enzymes
101
What is the palisade tissue in plants specialised for?
carry out photosynthesis
102
What do ciliated cells do and where are they found?
lining the trachea and bronchi of animals, moves mucus upwards
103
What is the circular loop of DNA in bacteria aka?
bacterial chromosome
104
Discuss heart muscles
atria receive blood, but ventricles pump blood so they have thicker, more muscular walls. the left ventricle has an especially thick wall to pump blood to the rest of the body
105
Describe how coronary arteries can get blocked.
Cholesterol deposits buid up inside the walls of arteries which make the artery wall stiffer and the lumen narrower, so it is more difficult for blood to flow through. Blood clots can form. Cardiac muscle does not get oxygen...heart stops beating (muscle cells cannot respire aerobically)
This is called CHD
106
How to reduce chances of getting CHD?
-do not smoke cigarettes
-taking care of diet: saturated fats is higher in meat than in plant-based foods, so plant oils instead. Eat fast food in moderation considering this
--regular exercise (keeps you fit, prevents excessive weight gain, deceases blood pressure, clears mind, causes chemical release in brain that increase feelings of well-being)
107
How can you hear a heartbeat?
using a stethoscope
108
What does ECG stand for?
electrocardiograph
109
How is the crazy swing of valves prevented?
tendons attached to valves stop them from swing too far, they have to be stopped in the closed position
110
How do capillaries perform their function?
Walls are thin so substances can get in and out easily, smallest capillary wall is only one cell thick.
allows delivery of named useful substances to tissues and removal of named waste ;
small lumen ;
short diffusion distance ;
slows down blood flow to maximise time for diffusion ;
gaps between capillary cells ;
111
... is squeezed by leg muscles when walking. This helps to push blood back up to your heart
large veins
112
Explain the blood vessel situation with the liver.
hepatic artery supplies oxygen, hepatic portal vein brings blood from the digestive system, all the blood leaves in the hepatic veins
113
What is a lesser known function of white blood cells?
clear up any dead body cells
114
Explain the process of phagocytosis
taking bacteria or other small structures into a cell's cytoplasm, and digesting them with enzymes
115
Explain why a leaf is considered to be an organ.
it is made of (named) tissues (in a leaf) ;
(tissues), working together / for a specific (named) function(s) ;
116
Explain how the palisade mesophyll is adapted.
* cells tightly packed
* positioned right below upper epidermis for light to reach chloroplasts
* vacuole keeps many chloroplasts towards the sides of the cells
117
Explain how the spongy layer is adapted.
* air spaces to allow diffusion of carbon dioxide and evaporation from cell surfaces
118
State the main function of the stomata.
Gas exchange. Diffusion of co2 in and oxygen out. Regulation of transpiration.
119
Predict and explain the effect of high humidity on the stomata.
reduces stomatal closure, reduced water vapour diffusion gradient, so gaurd cells do not lose water as much as in the first experiment.
120
Explain how proteins are made by a cell.
1. mRNA is copied from a gene
2. mRNA moves out the nucleus, to the cytoplasm
3. mRNA moves to + passes through the ribosome
4. ribosome makes proteins by assembling amino acids in an order determined by the base sequence of the mRNA
5. Protein synthesis uses energy
121
State two types of cell membrane proteins.
carriers ;
receptor(s) (proteins) ;
maltase / enzyme ;
122
Suggest reasons for the decrease in the number of bacterial infections resistant to erythromycin from 1993 to 1995.
*fewer doses used
*new vaccines and antibiotics used
*use antibiotics when essential eg: not for viral infections
*awareness of antibiotic resistance
*improved detection
*population reached herd immunity
*isolating infected individuals
123
Explain how bacteria become resistant to antibiotics.
-mutations occur (in some of the bacteria) ;
-(genetic) variation increases ability of bacteria to survive antibiotic
treatment ;
-bacteria with (antibiotic) resistance, survive / reproduce ;
pass on resistant allele to offspring
-increase in frequency of resistant, allele (in the population) ;
ref to natural selection / become (better) adapted (for the new
environment) ;
124
Some bacteria have a flagellum.
State the function of a flagellum.
movement/swimming
125
4th consumer is called?
quarternary consumer
126
Outline how the energy in the primary consumers in this aquatic food web is used to produce biomass in the secondary consumers.
Primary consumers contain chemical energy which is transferred to secondary consumers when they are eaten. Food particles are digested to make glucose available for respiration. Energy is used in protein synthesis for growth.
127
State the name of the growth responses observed in the bean roots and shoots.
upwards or downwards, positive or negative gravitropism
128
Shoot is growing straight...
auxin is evenly distributed in the shoot
129
Suggest why oxygen and water are required for germination.
(oxygen) aerobic respiration ;
(water) used in (named) cell process ;
(water) is a solvent ;
(water) used for turgor ;
130
The .............. produces trypsin which breaks down protein in
............. pH conditions. These conditions are created by a substance called ............ , which neutralises the gastric juices and also has an important role in the ............... of fats and oils.
The (small intestine) produces trypsin which breaks down protein in
(alkaline) pH conditions. These conditions are created by a substance called (bile), which neutralises the gastric juices and also has an important role
in the (emulsification) of fats and oils.
131
State two visible features that distinguish the fish from the amphibian.
Fish have fins and scaly skin
132
Describe how humans maintain a constant body temperature when the external
temperature decreases.
1 (internal temperature is maintained by) homeostasis
2 external temperature detected by, (thermo)receptors / sensory neurones in the skin ;
3 impulses (via sensory neurones) to the brain,
impulses from brain travel along motor neurone to effectors to cause a response.
4 change in internal temperature is detected by the brain, hypothalamus
5 (nerve) impulses are sent (via motor neurones) to (effectors in) the skin ;
Hair erector muscles contract. Hairs trap a layer of air which acts as insulation. Fatty tissue as well. Muscles contract and relax fast to release heat. Arterioles vasoconstriction to decrease blood flow to the surface, decreases heat loss. Sweat gland stops sweat production.
133
Role of fat layer?
insulation and energy reserve
134
Role of temperature receptors?
detect temperature changes
135
Explain the reasons for the difference in the numbers of mitochondria and chloroplasts
between the root hair cell and the palisade cell.
mitochondria:
1 more in root hair cell
2 aerobic respiration ;
3 to, release energy ;
4 for active, transport
5 against, a concentration gradient ;
chloroplasts:
6 in palisade only
7 no light reaches root hair cells
8 photosynthesis
9 contain chlorophyll ;
10 transfers energy from light to, energy in chemicals
11 to synthesise, glucose
136
Describe the results.
COICC
1. Conclusion: enzyme activity increases with temperature.
2. Overall: enzyme activity is higher when enzyme solution concentration is higher.
3. Individual: activity increases steeply then decreases, peaks, no records.
4. Comparison: cases remained the same while population fluctuated, delay
5. Changes: small changes after pH10, steepest change at 7-9, gradient changes
137
Explain the results.
CHD
1. Conclusion: increases as decreases
2. How: by increased transpiration
3. Details: describe everything, CO2 is required, light provides energy for photosynthesis
138
Sexual reproduction advantages.
Sexual reproduction allows for genetic variation, which results in different combinations of alleles. This variation enables adaptation to changing environments, increasing the overall chances of survival.
Animals: example of adaption advantage
Plants: population less susceptable to pest or disease, genetic diseases less likely, seed dipersal means less competition
139
Sexual reproduction disadvantages in plants.
1 requires two, parents, (named) pollinators
2 takes longer and more energy required
3 increased genetic variation means that some plants
might be less adapted to the environment
140
The dot on the villi is a cell which secretes mucus, what is it?
goblet cell
(ciliated cells lining the trachea and bronchi of animals sweep mucus upwards)
(cilia are tiny projections from some of the cells in the lining of the respiratory passages, cilia of many adjacent cells beat rhythmically)
141
places in the body where goblet cells are found
trachea, bronchi, bronchioles
142
State two features of amphibians that distinguish them from all other vertebrates.
eggs laid in water, larvae live in water while adults live on land
larvae have gills while adults have lungs
moist, slimy, smooth skin
143
Big round parts of frog eye..
Shield part of frog eye..
..pupil
..cornea
144
(rods and cones)
round part of neurone..
body part of neurone..
outside body part..
nucleus
cytoplasm
cell membrane
145
Suggest how the number and distribution of rod cells and cone cells across the retina of a nocturnal mammal would differ from a human retina.
more rods present and less cones
rods at fovea
(more rod in the middle)
146
Mitosis is a type of nuclear division which produces genetically identical cells.
It is important for growth, ....................... of tissues and .................... reproduction.
Just before mitosis the chromosomes are replicated and then the chromosomes
..................... so that the chromosome number is maintained in each daughter cell.
Meiosis is another type of nuclear division that is involved in the production of gametes. The chromosome number is halved from .................... to haploid resulting in genetically different cells. The fusion of the nuclei of two gametes formed by meiosis forms a .................... . This process is known as
........................... .
Mitosis:
repair of tissues
asexual
separate
Meiosis:
halved from diploid
zygote
fertilisation
147
How can mutation rates be increased?
ionising radiation and chemicals such as lead and mercury
148
Describe and explain how fish stocks can be managed sustainably sustainably and how overfishing can be prevented through conservation.
quotas, closed seasons, protected areas, ban harmful net types such as dredging nets, restriction on net mesh size, inspectors monitor catches in fishing boats
(mention of conservation points) **captive breeding
## Footnote
Quick Cats Play Ball Really Intensely
149
that identify the processes that:
* release the most energy per glucose molecule ........................................
* take place in yeast cells. .......................................................................
aerobic respiration
aerobic respiration and anaerobic respiration
| aerobic because of alcohol fementation
150
Why do heart muscle cells have many mitochondria?
Heart muscle cells need a constant supply of energy to contract continuously.
## Footnote
mention mitochondria function
151
What is the mineral ion used to make amino acids in plants?
nitrate ions
152
Why do red blood cells need no mitochondria?
RBCs are moved in the blood and take up oxygen by diffusion, so they don’t need energy for active transport. RBCs need space for haemoglobin, which is crucial for oxygen transport. In fact, it’s beneficial for RBCs not to use the oxygen they transport.
153
Why does the epithelium in the small intestine have many mitochondria?
Epithelial cells in the small intestine also have many mitochondria since they require energy for processes like active transport, which is essential for absorbing nutrients.
154
Explain the stuctural adaptions of veins.
veins:
4 large lumen to provide less resistance for blood flow and to carry larger volume of blood ;
5 thin walls --> blood is moved by contraction of surrounding muscle
6 valves to prevent backflow
| bmp
## Footnote
blood, moved, prevent
